a simple port scan.txt

当今

发信人: lgwu (乱世糊涂虫), 信区: Security 
标  题: a simple port scan 
发信站: 武汉白云黄鹤站 (Fri Jan 29 21:00:02 1999) , 站内信件 
  
static char sccsid[] = "@(#)pscan.c     1.0     (KRAD) 08/25/94"; 
                    #include <stdio.h> 
                    #include <sys/types.h> 
                    #include <sys/socket.h> 
                    #include <netinet/in.h> 
                    #include <netdb.h> 
  
                    #define MAX_PORT 1024 /* scan up to this port */ 
                    int s; 
                    struct sockaddr_in addr; 
                    char rmt_host[100]; 
  
                    int skan(port) 
                    int port; 
                    { 
                     int r; 
                        s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); 
                        if (s < 0) { 
                           /* fprintf("ERROR: socket() failed\n"); */ 
                           /* Changed to printf for my Linux 1.1.18 box */ 
                           printf("ERROR: socket() failed\n"); 
                           exit(0); 
                      } 
  
                        addr.sin_family = PF_INET; 
                        addr.sin_port = htons(port); 
                        addr.sin_addr.s_addr = inet_addr(rmt_host); 
  
                        r = connect(s,(struct sockaddr *) &addr, sizeof(addr)); 
  
                        close(s); 
                        if (r==-1) { 
                           return (1 == 0); 
                        } 
  
                        return (1 == 1); 
                    } 
  
                    main(argc,argv) 
                    int argc; 
                    char *argv[]; 
                    { 
                     int a,b,c,d,e,f; 
                     struct hostent *foo; 
                    struct servent *bar; 
  
                       if (argc < 2) { 
                          fprintf(stderr,"usage: %s <host> [highest port]\n",arg 
v[0]); 
                          exit(0); 
                       } 
  
                       if (sscanf(argv[1],"%d.%d.%d.%d",&a,&b,&c,&d) != 4) { 
                          foo = gethostbyname(argv[1]); 
                          if (foo == NULL) { 
                             fprintf(stderr,"error: cannot resolve host %s\n",ar 
gv[1]); 
                             exit(0); 
                          } 
                          sprintf(rmt_host,"%d.%d.%d.%d",(unsigned char )foo->h_ 
addr_list[0][0], 
                                  (unsigned char ) foo->h_addr_list[0][1], 
                                  (unsigned char ) foo->h_addr_list[0][2], 
                                  (unsigned char ) foo->h_addr_list[0][3]); 
                       } else { 
                          strncpy(rmt_host,argv[1],99); 
                       } 
  
  
                       if (argc > 2) { 
                          f = atoi(argv[2]); 
                       } else 
                          f = MAX_PORT; 
  
                       fprintf(stdout,"Scanning host %s - TCP ports 1 through %d 
\n",rmt_host,f); 
  
                       for (e =1;e<=f;e++) { 
                        char serv[100]; 
                          if (skan(e)) { 
                             bar = getservbyport(htons(e),"tcp"); 
                             printf("%d (%s) is running.\n",e,(bar == NULL) ? "U 
NKNOWN" : 
                                    bar->s_name); 

                          } 
                       } 
                    } 
 /* This simple port scan program can be found in /var/log/messages */ 
But if u use nmap( half connect,NULL connect,a normal TCPwarp couldn't 
find it out. As a patch,you can use tcplog.I  posted it before. 
  
  
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